Environmental Rules in Alameda County, CA (2026)

4 county-level rules, plus city-specific rules for 6 cities in Alameda County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Alameda County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Stormwater Management

Unincorporated Alameda County bans discharging anything but stormwater into its storm drains, creeks or the bay, with narrow exemptions for irrigation runoff, pool draining and similar low-risk flows.

Stormwater Discharge Rules in Alameda County

Significant Restrictions

Alameda County Code § 13.08.070(A)

Except for those discharges described in subsection B of this section, the discharge of nonstormwater discharges to the waters of the United States or to the county stormdrain system is prohibited.

Full ordinance details →Official source ↗

Erosion Control

Grading operations in unincorporated Alameda County must follow erosion and sediment control standards under § 15.36.600, including limits on rainy-season work and required long-term stabilization of disturbed slopes.

Erosion Control Rules in Alameda County

Some Restrictions

Alameda County Code § 15.36.600

The following shall apply to the control of erosion and sediment from grading operations: A. Grading plans shall be designed with long-term erosion and sediment control as a primary consideration. B. No grading operations shall be conducted during the rainy season except upon a clear demonstration, to the satisfaction of the director of public works, that at no stage of the work will there be a...

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Flood Zones

Development in FEMA-mapped flood hazard areas of unincorporated Alameda County must meet the county's Floodplain Management Regulations, tied to Flood Insurance Rate Maps adopted since the county joined the NFIP in 1981.

Flood Zone Development Rules in Alameda County

Some Restrictions

Alameda County Code § 15.40.110

The County of Alameda was accepted for participation in the National Flood Insurance Program on April 15, 1981. The Flood Insurance Study for Alameda County, California and Incorporated Areas dated August 3, 2009, and all subsequent amendments and revisions, and the accompanying Flood Insurance Rate Maps (FIRM), and all subsequent amendments and revisions to such maps, are hereby adopted by ref...

Full ordinance details →Official source ↗

Flood Elevation Requirements

New structures in the county's combining FF (flood fringe) zoning district must set their lowest floor at least one foot above the adopted 100-year flood level under § 17.30.090.

Flood Elevation Rules in Alameda County

Some Restrictions

Alameda County Code § 17.30.090

No structure shall be permitted in a combining FF district which does not have its lowest floor, including basement floor, at least one foot above the level of the one hundred (100) year flood adopted for the particular area.B.No waste treatment, sanitary transportation, water supply or other facility utilized to service structures or their inhabitants in a combining FF district shall be constr...

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